OMIS图像条带噪音消除方法研究

分析了OMIS高光谱图像条带噪音产生的主要原因及条带噪音的特点.提出了两种改进的空域和小波域OMIS条带噪音消除新方法.比较了实验图像和数据.结果表明,两种新方法均具有良好的消除OMIS条带噪音的能力,并能较好地保持图像的纹理细节信息,效果明显优于原有方法.     

Research on Preparation Methods of Carbon Nanomaterials Based on Self-Assembly of Carbon Quantum Dots

Here, based on self-assembly of carbon quantum dots (CDs), an innovative method to prepare nanomaterials under the action of a metal catalyst was presented. CDs were synthesized by a one-step hydrothermal method with citric acid (CA) as the carbon source, ethylenediamine (EDA) as the passivator and FeSO₄•7H₂O as the pre-catalyst. In the experiment, it was found that the nano-carbon films with a graphene-like structure were formed on the surface of the solution. The structure of the films was studied by high-resolution transmission electron microscopy (HRTEM), Fourier transform infrared (FT-IR), etc. The results demonstrated that the films were formed by the self-assembly of CDs under the action of the gas–liquid interface template and the metal catalyst. Meanwhile, the electrochemical performance of the films was evaluated by linear cyclic voltammetry (CV) and galvanostatic charge discharge (GOD) tests. In addition, the bulk solution could be further reacted and self-assembled by reflux to form a bifunctional magnetic–fluorescent composite material. Characterizations such as X-ray diffractometer (XRD), fluorescence spectra (FL), vibrating sample magnetometer (VSM), etc. revealed that it was a composite of superparamagnetic γ-Fe₂O₃ and CDs. The results showed that self-assembly of CDs is a novel and effective method for preparing new carbon nanomaterials.     

Concurrent suppression of Aβ aggregation and NLRP3 inflammasome activation for treating Alzheimer's disease

Alzheimer''s disease (AD) is a neurodegenerative illness accompanied by severe memory loss, cognitive disorders and impaired behavioral ability. Amyloid β-peptide (Aβ) aggregation and nucleotide-binding oligomerization domain (NOD)-like receptor protein 3 (NLRP3) inflammasome play crucial roles in the pathogenesis of AD. Aβ plaques not only induce oxidative stress and impair neurons, but also activate the NLRP3 inflammasome, which releases inflammatory cytokine IL-1β to trigger neuroinflammation. A bifunctional molecule, 2-[2-(benzo[d]thiazol-2-yl)phenylamino]benzoic acid (BPBA), with both Aβ-targeting and inflammasome-inhibiting capabilities was designed and synthesized. BPBA inhibited self- and Cu²⁺- or Zn²⁺-induced Aβ aggregation, disaggregated the already formed Aβ aggregates, and reduced the neurotoxicity of Aβ aggregates; it also inhibited the activation of the NLRP3 inflammasome and reduced the release of IL-1β in vitro and vivo. Moreover, BPBA decreased the production of reactive oxygen species (ROS) and alleviated Aβ-induced paralysis in transgenic C. elegans with the human Aβ₄₂ gene. BPBA exerts an anti-AD effect mainly through dissolving Aβ aggregates and inhibiting NLRP3 inflammasome activation synergistically.

Bifunctional molecule BPBA inhibits Aβ aggregation and NLRP3 inflammasome activation, thereby decreasing ROS and IL-1β in vitro and vivo; it synergistically prevents Alzheimer''s disease via alleviating Aβ neurotoxicity and reducing neuroinflammation.     

农残水平测试中数据多态性分析及指定值估计研究

对全国农残水平测试中毒死蜱、氯氰菊酯数据进行统计分析,在数据统计分布特征研究基础上,使用内核密度估计进行数据多态性分析,使用bootstrap模拟取样法对数据样本值重复取样,以获得稳健的水平测试样品待测物含量代表值估计、标准误差及置信区间描述,证明以bootstrap模拟取样法获取的均值与标准偏差作为有限单次样本代表值是合理、有效的,解决了四分位稳健统计方法对非正态多态分布代表值估计不稳定问题及取样理论中取样样本数限制的瓶颈,为能力验证计划指定值的获取提供了一种新方法。     

壳聚糖的基质辅助激光解吸电离飞行时间质谱分析

利用基质辅助激光解吸电离飞行时间质谱(MALDI-TOF-MS)分析甲壳素脱乙酰化降解产物——壳聚糖,对基质、制样方法等影响MALDI-TOF-MS测定结果的因素进行了研究。实验发现,以2,5-二羟基苯甲酸(DHB)为基质,二次结晶法制样分析壳聚糖,既获得了壳聚糖的分子量信息,又可以推断壳聚糖的脱乙酰度,对壳聚糖的制备及其质量与性能控制有着十分重要的指导意义。     

单轴拉伸下氧化锆纳米柱相变机理的分子动力学研究

通过分子动力学模拟,观察到[001]取向的四方氧化锆纳米柱在拉伸载荷下具有两个线弹性变形的应力-应变关系.这一现象是四方结构向单斜结构相变的结果 .为了进一步阐明应力-应变曲线,进行了包括晶体结构分析和原子应变计算在内的详细研究.晶格取向强烈影响塑性变形机制,即[001]和[111]取向的纳米柱在拉伸载荷下经历相变,而沿[110]取向的纳米柱导致脆性断裂.观察到显著的温度效应,随着温度从300K升高到1500K,弹性模量从573.45GPa线性降低到482.65GPa.此外,还用轻推弹性带(NEB)理论估算了相变能垒,观察到相变能垒随温度的升高而降低.这一工作将有助于加深对氧化锆的四方相到单斜相转变和纳米尺度力学行为的理解.     

一种基于萘酰亚胺的检测细胞内pH值的荧光探针及其生物成像应用

细胞内溶酶体的pH值对细胞自噬、吞噬、酶加工等各项生命活动有着重要影响.细胞核是真核细胞中最大的细胞器,控制着生物体内的遗传和代谢过程,参与代谢过程的酶对pH值的变化很敏感.因此,研究细胞体内的pH值变化至关重要.我们设计并以简单的两步反应合成了一种新型荧光探针NpH-1.该探针以萘酰亚胺作为荧光团,以吗啉基团作为对p...     

Optimization of Ultrasound-Assisted Cellulase Extraction from Nymphaea hybrid Flower and Biological Activities: Antioxidant Activity,Protective Effect against ROS Oxidative Damage in HaCaT Cells and Inhibition of Melanin Production in B16 Cells

In this study, ultrasonic-assisted cellulase extraction (UCE) was applied to extract flavonoids and polyphenols from the Nymphaea hybrid flower. The extraction conditions were optimized using the response surface method (RSM) coupled with a Box-Behnken design. The crude extract of Nymphaea hybrid (NHE) was further purified using AB-8 macroporous resins, and the purified extract (NHEP) was characterized by FTIR and HPLC. In vitro activity determination by chemical method showed that NHEP displayed strong free radical scavenging abilities against the DPPH and ABTS radicals, good reduction power, and hyaluronidase inhibition. The cell viability by CCK-8 assays showed that NHEP had no significant cytotoxicity for B16 and HaCaT cells when the concentration was below 100 μg/mL and 120 μg/mL, respectively. NHEP with a concentration of 20–160 μg/mL can more effectively reduce the ROS level in H₂O₂ damaged HaCaT cells compared with 10 μg/mL of VC. The 40 μg/mL of NHEP had similar activity against intracellular melanin production in the B16 melanoma cells compared with 20 μg/mL Kojic acid. Good activities of antioxidation, whitening and protective effect against H₂O₂-induced oxidative damage promote the potential for NHEP as a functional raw material in the field of cosmetics and medicine.     

液质联用检测人体血浆中的阿奇霉素

采用高效液相色谱串联质谱技术(HPLC-MS/MS)测定人体血浆中阿奇霉素的浓度. 选用Lichrospher CN 柱, 流动相为V(乙腈)∶V(水)=40∶60(水中含体积分数为0.1%的甲酸和质量分数为0.1%的醋酸铵), 电喷雾离子源正离子方式检测. 该方法在2.34~600 ng/mL范围内线性关系良好, 定量下限为2.34 ng/mL(S/N>10), 回收率94.13%~97.42%, 基质效应92.50%~107.87%, 日内和日间测定药物浓度的相对标准偏差(RSD)均小于10.0%. 用该方法测定了24名男性健康志愿者单剂量口服500 mg阿奇霉素试剂和参比制剂于192 h内的血药浓度, 并进行了生物等效性研究.